Evaluation of CERES-Rice model (DSSAT 4.5) for simulating the response of rice (Oryza sativa) cultivars to age of seedlings in temperate Kashmir

A field experiment was conducted at Agronomy Farm of Sher-e-Kashmir University of Agricultural Sciences and Technology of Kashmir, Shalimar during the rainy season (kharif) 2010 and 2011 to simulate the effect of age of seedling on growth and yield of 3 rice (Oryza sativa L.) cultivars viz. ‘Jhelum’, ‘SKUA 403’ and ‘SR 1’. The experimental data were used for CERES-Rice model calibration and development of the genetic coefficients of these rice cultivars. The predicted and observed dates of phenological events were in close agreement. Similarly, the predicted and observed grain, straw and biological yields were also very close. Among cultivars, ‘Jhelum’ recorded the highest grain yield and harvest index, whereas straw yield was highest in ‘SKUA 403’. Setting in of different phenological stages occurred earlier in ‘Jhelum’ compared to other cultivars. Forty days old seedlings performed better than 30- and 20- days-old seedlings in all respects. Their growth and yield-attributing characters were significantly higher than young aged seedlings. The time taken by 40-days-old seedlings to different phenological stages was also lesser than that of 30- and 20-days-old seedlings. Grain, straw, biological yields and harvest index of 40-days-old seedlings were also significantly better than 30- and 20-days-old seedlings. Regarding simulation studies similar results were obtained with permissible deviations. Simulation studies with respect to age of seedling and sowing time showed better results in terms of crop growth and yield when the crop was sown earlier with 40-days-old seedlings. Sowing earlier with aged seedling gave better results in terms of growth and yield as compared with late sown with younger seedlings. Hence for realizing optimum rice yields, 40-days-old seedlings of rice cultivar ‘Jhelum’ should be transplanted in the field by 10–11 June.